Isolation of the elusive [Ru(bipy) 3 ] + : a key intermediate in photoredox catalysis.

Photoredox catalysis has flourished in recent years, but due to its widespread utility applications have grown faster than mechanistic understanding. In this report we help to address this deficit by isolating and characterising one of the intermediates of the iconic photocatalyst [Ru(bipy) 3 ] 2+ , and testing its initial photoreactivity towards common substrates.